Numpy from wheel on armv7l: Original error was: No module named 'numpy.core._multiarray_umath'

Question

I'm trying to set up the numpy module for python 3.9.8 on an armv7l device with no internet connection.

I've tried many versions, but I keep getting this error:

Python 3.9.8 (main, Jan 13 2022, 11:11:29) 
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/numpy/core/__init__.py", line 23, in <module>
    from . import multiarray
  File "/usr/lib/python3.9/site-packages/numpy/core/multiarray.py", line 10, in <module>
    from . import overrides
  File "/usr/lib/python3.9/site-packages/numpy/core/overrides.py", line 6, in <module>
    from numpy.core._multiarray_umath import (
ModuleNotFoundError: No module named 'numpy.core._multiarray_umath'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.9/site-packages/numpy/__init__.py", line 144, in <module>
    from . import core
  File "/usr/lib/python3.9/site-packages/numpy/core/__init__.py", line 49, in <module>
    raise ImportError(msg)
ImportError: 

IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!

Importing the numpy C-extensions failed. This error can happen for
many reasons, often due to issues with your setup or how NumPy was
installed.

We have compiled some common reasons and troubleshooting tips at:

    https://numpy.org/devdocs/user/troubleshooting-importerror.html

Please note and check the following:

  * The Python version is: Python3.9 from "/usr/bin/python3"
  * The NumPy version is: "1.22.1"

and make sure that they are the versions you expect.
Please carefully study the documentation linked above for further help.

Original error was: No module named 'numpy.core._multiarray_umath'

I use command pip3 install 'numpy_file'.whl

I downloaded the wheel files from: https://www.piwheels.org/project/numpy/ for armv7l architecture

I already tried version from numpy-1.19 to numpy-1.22. This is the content of numpy/core directory:

root@triton1:~# ls /usr/lib/python3.9/site-packages/numpy/core/
__init__.py
__init__.pyi
__pycache__
_add_newdocs.py
_add_newdocs_scalars.py
_asarray.py
_asarray.pyi
_dtype.py
_dtype_ctypes.py
_exceptions.py
_internal.py
_internal.pyi
_machar.py
_methods.py
_multiarray_tests.cpython-39-arm-linux-gnueabihf.so
_multiarray_umath.cpython-39-arm-linux-gnueabihf.so
_operand_flag_tests.cpython-39-arm-linux-gnueabihf.so
_rational_tests.cpython-39-arm-linux-gnueabihf.so
_simd.cpython-39-arm-linux-gnueabihf.so
_string_helpers.py
_struct_ufunc_tests.cpython-39-arm-linux-gnueabihf.so
_type_aliases.py
_type_aliases.pyi
_ufunc_config.py
_ufunc_config.pyi
_umath_tests.cpython-39-arm-linux-gnueabihf.so
arrayprint.py
arrayprint.pyi
cversions.py
defchararray.py
defchararray.pyi
einsumfunc.py
einsumfunc.pyi
fromnumeric.py
fromnumeric.pyi
function_base.py
function_base.pyi
generate_numpy_api.py
getlimits.py
getlimits.pyi
include
lib
memmap.py
memmap.pyi
multiarray.py
multiarray.pyi
numeric.py
numeric.pyi
numerictypes.py
numerictypes.pyi
overrides.py
records.py
records.pyi
setup.py
setup_common.py
shape_base.py
shape_base.pyi
tests
umath.py
umath_tests.py

I also tried the method to change the name of that files and remove this part: "cpython-39-arm-linux-gnueabihf" or just this "arm-linux-gnueabihf", but it's not working.

I'm stuck, so please, if you have any idea, let me know.Thanks!

UPDATE: The problem was that I've installed a numpy wheel for armv7 hard-float system, while my system was an armv7 soft-float system. So, I rebuilt the system in hard-float strategy and now the numpy is working.